The Session Initiated Protocol is a text-based signaling protocol that can be used for controlling networked multimedia communication sessions such as voice and video calls over Internet Protocol (IP). SIP is commonly used for setting up and tearing down voice and video calls between two parties (e.g., unicast sessions) or more than two parties (e.g., multicast sessions) with one or several media streams. SIP is commonly used for large scale multiparty conferencing (e.g., up to hundreds of participants) using multicast techniques. Participants in SIP conferencing may be spread across a varied network topography and may communicate with each other via the SIP conference using numerous protocols including public switched telephone network (PSTN), mobile telephony (e.g., 2G, 3G, etc.), wireless broadband, wireline broadband, etc.
Energy management is becoming an increasingly important issue in network communications. In the past, many service providers, including Internet service providers, enterprise service providers, and others, ignored or de-prioritized energy management in an effort to provide maximal data handling capacity. However, the current business climate includes an emphasis on more energy efficient operations, which is leading service providers and others to look toward energy management as a higher priority design consideration than in the past.